This is an application for renewal of an Institutional Research Training Grant within the Department of Pediatrics at Washington University School of Medicine. The long-term objective is to foster the growth and development of pediatric physician-scientists who are prepared to pursue independent academic careers investigating important issues in childhood infection and immunity. The specific aim of this proposal is to utilize the unique resources of the institution, including the Center for Infectious Diseases Research, the Center for Immunology, and the Division of General Medical Sciences, to maintain a training program with a participating faculty of pediatricians, basic scientists, and clinical investigators who share common interests and Frequent investigative and scholarly interactions. The program is intended to provide funding for an initial two years of investigation and emphasizes the application of cell and molecular biologic approaches and rigorous clinical and epidemiologic methods to address common issues in childhood infection and immunity. Trainees will have access to sufficient space and resources and will benefit from the numerous educational activities within the institution, including didactic coursework, journal clubs, and relevant seminars. The program director will utilize an executive committee to select candidate trainees, to review the scholarly progress of trainees, and to obtain continuing advice with respect to operation of the program. The substantial collaboration of established pediatric physician-scientists and basic and clinical investigators in other departments pursuing questions in microbial pathogenesis, immunology, and clinical infectious diseases provides a unique opportunity for the training of selected individuals in the application of experimental methods to the treatment and prevention of infectious and immunologic diseases in children. As such, this program should foster the development of new pediatric scholars to lead the way for future advances in these important areas of child health.